Shortly after the Tampa appearance, Clinton announced she had chosen U.S. Sen. Tim Kaine of Virginia as her running mate.
"I'm thrilled to announce my running mate, @TimKaine, a man who's devoted his life to fighting for others," Clinton said in a Twitter post.
Clinton's visit to Tampa came a day after the GOP convention wrapped up in Cleveland —- and three days before the start of the Democratic National Convention in Philadelphia. She focused much of her remarks on the GOP event and on the Republican nominee, real estate and entertainment magnate Donald Trump.
Characterizing Trump's acceptance speech Thursday night as dominated by "fear and resentment," Clinton painted her opponent as a divisive and angry threat to the nation's future.
"No matter what your political leanings, I think we can all agree that never in the history of conventions, certainly, but I think even more broadly, have we moved forward together by pointing fingers and scapegoating and blaming people," she said.
Clinton also made light of the verbal attacks on her that dominated much of the convention.
"It was kind of perversely flattering," she joked, adding that the Democratic convention —- which kicks off Monday —- would have a "very different vision."
Clinton drew loud applause from a crowd of more than 3,500 supporters by evoking Texas Republican Sen. Ted Cruz, who was essentially booed off the stage Wednesday night when he refused to endorse Trump.
"I never thought I would say these words but Ted Cruz was right. … Vote your conscience," Clinton said, quoting the onetime presidential candidate.
The former secretary of state began a tri-city swing through Florida on a somber note, leaving flowers at a memorial to the victims of the June 12 massacre at Pulse, a gay nightclub in Orlando that was the site of the worst mass shooting in the nation's history. Clinton will appear at a rally Saturday at Florida International University in Miami.
After meeting earlier with survivors, victims' family members and first responders in Orlando, Clinton launched an attack during the Tampa rally on Trump's comments Thursday night that "I alone can fix" the nation's problems.
The police captain in charge of the team that rescued clubgoers during the attack "didn't say I can fix it alone," Clinton said.
"I've never heard of an American leader, or at least someone who wants to be an American leader, claiming that he's all we need. … That's not a democracy, my friends. As I recall, we had a revolution to make sure we didn't have someone who said I can fix it alone," she said.
Calling for more "love and kindness," Clinton pointedly contrasted herself with her Republican opponent, striking a decidedly upbeat note throughout her 30-minute speech and ending by expressing empathy for people "who are feeling insecure and anxious about their lives."
"I know there's a lot of angst. I understand all that. And I respect those who have legitimate concerns and questions. But I've never known America to quit on ourselves. I've never known us to give up on the face of tough challenges … to retreat in the kind of isolation that was being advertised at their convention," she said. "That is not who we are. Those are not the values that made us a great country."
Clinton closed with a play on words for the supporters who crowded into a fairground hall to hear a speech that set the stage for what Democrats can expect at the Philadelphia party convention.
"Just remember, love trumps hate," she said.
Perry Miller, 86, and his wife, Sandy, traveled from nearby Sun City Center to show their support for Clinton.
"She was able to take advantage of all the ridiculous statements that Trump made," Sandy Miller said.
Florida's 29 electoral votes make it the crown jewel of the states at play in the presidential election.
"If you look at all the battleground states in the country, and if you add up all the votes over the last six presidential elections, we're also the closest battleground state in the country," said Steve Schale, a Democratic consultant who ran President Barack Obama's Florida campaign in 2008. "We're the biggest and the most competitive. So it makes perfect sense to come and lay an early marker down here."
While a Florida victory is considered an essential element in the path to the White House for Democrats, the state may be even more critical for the GOP —- Calvin Coolidge in 1924 was the last Republican candidate to win the presidency without the Sunshine State's support.
And Clinton's stops in Tampa and Orlando were likely a harbinger of a focus on the I-4 corridor between now and November.
"Our success in the I-4 corridor is essential to our winning," Clinton said.
Tampa Bay is home to "a lot of persuadable targets, persuadable voters," Ashley Walker, a Democratic consultant who coordinated Obama's 2012 campaign in Florida, said in a telephone interview Friday. "So seeing her visit there today is not a surprise."
Clinton can also be expected to focus on Hispanics, who make up a growing number of voters along the I-4 corridor and who have been alienated by Trump's views on issues such as immigration. Hispanic voters "will make or break" the presidential election, according to Democratic consultant Ana Cruz, who lives in Tampa.
Waiting beneath gray skies in a long line to enter the fairgrounds arena, Angel Cantillano called Trump's positions on immigration insulting.
"I don't like his ego," Cantillano, who was born in Honduras and has lived in Lakeland for 23 years, said. "He doesn't realize we are legal immigrants. He's probably a good businessman, but I don't think he's a good politician."
Punctuating the significance of battleground Florida's role in the 2016 presidential election, Democratic candidate Hillary Clinton delivered what was essentially a rebuttal to the Republican National Convention before an enthusiastic crowd Friday in Tampa.